High sensitivity vibrating reed magnetometer

Abstract

A high sensitivity vibrating reed magnetometer useful for measurements on very small ferromagnetic particles is described. The reed is made of gold wire (18 μm in diameter, 10 mm long). The mechanical vibrations of the reed are converted directly to an ac voltage by a piezoelectric ceramic. Using a lock-in amplifier magnetic moments as small as 10−9 Acm2 can be detected.